The radio frequency (RF) spectrum is a limited commodity. Only a small portion of the spectrum can be assigned to each communications industry. The assigned spectrum, therefore, must be used efficiently in order to allow as many frequency users as possible to have access to the spectrum. Multiple access modulation techniques are some of the most efficient techniques for utilizing the RF spectrum. Examples of such modulation techniques include time division multiple access (TDMA), frequency division multiple access (FDMA), and code division multiple access (CDMA).
In order to attract and retain subscribers, wireless service provider frequently introduce end-user services that are desirable to consumers. These end-user services may include broadcast services provided via the wireless networks. Broadcast services may include advertisements, live news, sports highlight and scores, entertainment broadcasts, and the like that are broadcast from wireless network base stations over a particular geographical area for a fixed length of time.
Broadcast services are likely to play a significant role in wireless networks of the future. However, this presents problems with regard to the efficient utilization of the hardware and software resources in the base stations of a wireless network. Each broadcast message transmitted by one or more sectors of a base station requires a channel element to transmit the message. If there are no mobile stations in the listening area of a base station sector that are subscribing to the broadcast message, the channel element transmitting the broadcast message in that base station sector is wasted. Furthermore, if broadcast messages are transmitted by different base station in the same general time frame, but are not precisely synchronized, a mobile station may receive several substantially unsynchronized broadcast signals that are all too weak or noisy to properly detect.
There is therefore a need in the art for improved systems and methods for transmitting broadcast messages to mobile stations in a wireless network. In particular, there is a need for an improved broadcast controller that minimizes the number of wireless channel resources that are required to perform a message broadcast. More particularly, there is a need for an improved broadcast controller that increases the likelihood that a mobile station will properly receive a broadcast message.